The Small Molecule Screening Facility fosters collaborative work that leads to the identification of new small molecule agents that inhibit cancer phenotypes in cellular or animal models and that can be further developed for clinical evaluation in human cancer patients. The facility uses high throughput screening technologies and libraries of small molecule, drug-like chemicals to identify new chemical modulators of biological assays provided by UW investigators, and establishes and performs biological assays on compounds provided by UW chemists to help identify a compound's biological activity, potency or mode of action. . The biological endpoints address basic questions about viral entry, bacteriology, protein-DNA binding, protein-protein binding, anti-bacterial drug development, and anti-cancer drug development. The screens employ both cell-based assays of gene expression and specific biochemical targets including protein-protein interactions, enzyme activity and disturbance of protein-DNA binding. The assays have utilized several different modes of detection including changes in luminescence or fluorescence, changes in homogeneous time-resolved fluorescence, and fluorescence polarization. Facility staff work with UW scientists at the earliest stages of assay development to optimize the cell number per well, detection conditions in the multi-well plate reader and establish the statistical variation in the assay conditions with respect to well-to-well and plate-to-plate variation. f ' The facility encourages greater involvement in cancer research by UW chemists, biologists and engineers through their interests in small molecule chemistry and new screening methodologies.